A network provides for communication among members of the network. Wireless networks allow connectionless communications. Wireless local area networks are generally tailored for use by computers and may employ sophisticated protocols to promote communications. Wireless personal area networks with ranges of about 10 meters are poised for growth, and increasing engineering development effort is committed to developing protocols supporting wireless personal area networks.
With limited range, wireless personal area networks may have fewer members and require less power than wireless local area networks. The IEEE (Institute of Electrical and Electronics Engineers) is developing the IEEE 802.15.3a wireless personal area network standard. The term piconet refers to a wireless personal area network having an ad hoc topology comprising communicating devices. Communication among devices that are members of a piconet may be coordinated by a piconet coordinator (PNC). Piconets may form, reform, and abate spontaneously as various wireless devices enter and leave each other's proximity. Piconets may be characterized by their limited temporal and spatial extent. Physically adjacent wireless devices may group themselves into multiple piconets running simultaneously.
One proposal to the IEEE 802.15.3a task group divides the 7.5 GHz ultra wide band (UWB) bandwidth from 3.1 GHz to 10.6 GHz into fourteen bands, where each band is 528 MHz wide. These fourteen bands are organized into four band groups each having three 528 MHz bands and one band group of two 528 MHz bands. An example first device that is a member of a piconet, such as a transceiver, may transmit a first MB-OFDM symbol in a first 312.5 nS duration time interval in a first frequency band of a band group, a second MB-OFDM symbol in a second 312.5 nS duration time interval in a second frequency band of the band group, and a third MB-OFDM symbol in a third 312.5 nS duration time interval in a third frequency band of the band group. An example second device belonging to a different piconet may also transmit concurrently with the first device using the same band group, wherein the second device distinguishes its transmissions from those of the first device by using different time-frequency codes and a distinguishing preamble sequence. This method of members of different piconets sharing a band group by transmitting on each of the three 528 MHz wide frequencies of the band group may be referred to as time frequency coding or time frequency interleaving (TFI). Alternatively, members of one piconet may transmit exclusively on one frequency band of the band group while members of another piconet may transmit exclusively on another frequency band, which may be referred to as fixed frequency interleaving (FFI).